I have three 4-OP FM synths I live and die by:
I won’t talk about the Digitone, theres enough of that here. (probably the synth I’m most productive with and I have bunch)
Prologue/nts-1/minilogue XD ->
tx81z ->
Shameless plug heres a track I made using only these three synths for sounds sources and a pioneer tape machine.
Any videos out there showing the Node workflow on the Minilogue XD? Couldn’t find anything
Norand Mono can work as 4-op FM between the two oscillators, the filter, and LFOs. Not its main purpose but I’ve tried it just to do it and it works.
preen fm is always an option…there are few exotic things out there, like the dfam synth and the opera rotas…
dfam:
opera rotas:
please checkout pages 6 & 7 
why’s the FB01 getting no love in this thread!?, portamento, 8 voice poly. rude sound. cheap as kebab shop chips.
I’m just gonna say while there have been a lot of great options listed here I don’t know if any of them fully fill the Akemie’s castle void if that is what you really are wanting. Especially if mixing the chord and other outputs. I would say maybe just dive in and make a little rig around it. You could start with just a Pam’s and Akemie’s but I would probably add in a midi input a mixer an maybe a few little envelopes. It doesn’t help the ALM make great demos of there stuff. As someone who recently dove into a little ALM case, their stuff is just stupid good.
Can confirm that a Korg DS-8 is about the dirtiest 4op style FM synth I’ve heard or used. So much, IMO, awesome aliasing! Still relatively affordable too(when you can find them!).
Love the tq5 but worth mentioning that it’s now quite a bit more expensive than the tx81z, I assume because people realized how awesome it looks.
EssenceFM is Probably the ultimate fm hardware if you don’t want retro flavor. Just ignore the extra 2 operators if you only need 4!
that Rotas sounds lovely
None of these are perfect… but there is no perfect synth. It really comes down to what’s most important to you and what you’re willing to trade off.
If you decide on one that delivers on your top priorities, there’s a good chance the other things it doesn’t do as well won’t end up bothering you.
Does it have to be 4 operators? I got a guy who can hook you up with 3.5 operators for a steal.
Maybe a silly question, but what do you mean by “dirty” exactly?
Even a pair of FM operators get’s really “dirty” quickly, if a tiny amount of “feedback” is applied.
His customer service is great to be frank. Better than a lot of huge companies!
only one I’ve had is the mega fm. build was a little flimsy imo. materials feel a bit cheap - the metal is thin, unit feels a bit hollow, sliders a touch wobbly. not amazing but not terrible.
sounded great tho
Not silly at all. I don’t know enough about FM synthesis to speak about this (never owned an FM synth, I just did some reading/listening)
I think it may depend on the aliasing, the amount/quality of noise and how many operators can feedback, but I’m just speculating.
I’m surprised no one has mentioned the Sonicware XFM. 4 operator, cheap, and lots of editing options. Mix FM sounds with each other in multiple ways OR dive in and edit each operator. You can even do a feedback ring and it doesn’t have set algorithms (though you can pick one if you want). Check out Chris Lody’s videos on the XFM on YouTube.
Yeah, I hadn’t realized how expensive they’d become… Got mine 10 years ago for very cheap but prices now are simply absurd!
The 4OP FM synth in the M8 tracker is fantastic and can sound quite gnarly, especially considering each operator has feedback. Maybe a little overkill for “just” the FM synth, but on the other hand the device itself is great as well.
I’d love to get the M8 cause I really like trackers. But for now I’m looking for something a bit easier to use for learning FM synthesis.
Also, what draws me toward the Reface Dx (plus controller) is the possibility to tweak the sound in real time - kinda like this
